Grinding machine



June 6, 1944.

M; AHNERT GRINDINGMACHINE Filed Dec. 12, 1941` 5 Sheets-Sheet 1 June s, 1944. M, AHNERT 2,350,710

GRINDING MACHINE Filed Dec. 12. 1941 5 sheets-sheet 2 /n ven/or MAX Afm/Eer June 6, 1944. M. AHNERT 2,350,710

GRINDING MACHINE Filed Dec. 12, 1941 5 Sheets-Sheet 3 75 88 /n ven/or MA x A HNE/2 T June 6, 1944. l M, AHNERT 2,350,710

GRINDING MACHINE Filed De. l12, 1941 5 Sheelts-Sheet 4 f l xq m n )o Q w /f 3 a vl 3 w l tg se Y H "n /n ven/or MAX AHA/5,97'

lay l June 6, 1944. M. AHNERT Y2,350,710

GRINDING MACHINE Filed Deo. l2, 1941 5 Sheets-Sheet 5 MAx Aff/veer Allo/ wey Patented June 6, 1944 GRINDING MACHINE Max Ahnert, Aschersleben, Germany; vested in the Alien Property Custodian Application December 12, 1941, Serial No. 422,615 In Germany June 8, 1940 13 Claims.

The object of my invention is a grinding machine adapted to accurately finish the internal walls of a prismato passage-way extending through a Work piece and having a polygonal, more particularly a rectangular, cross-section. A more specific object is to provide a machine of this kind which is simple in design and operation and combines rigidity with great accuracy.

A further object is to provide a machine of this type in which the guides for producing the relative motion of the tool and the work piece shall have comparatively large Vguiding surfaces which are so disposed that they can be eiciently protected from chips and dust. A further object is to increase the working range of the machine so as to render it capable of Working on work pieces of a great variety of different dimensions.

I attain these and other objects by mounting one or more grinding discs on a beam extending through the passage-way of the work piecev and by journalling the beam at both of its "ends in spaced standards of a frame provided with a guideway extending parallel to the beam land accommodating a slide carrying the work piece. Although narrow limits are set to the diameter of the beam by the cross-section f the passage-wam' large distance of the standards and a small diam-l eter of the beam. I produce the relative motion between the Work piece and the grinding wheels by adjustably but rigidly mounting the grinding spindle on the beam and by imparting the .feed motion to the work piece only. To this end, I preferably provide a transverse guide care rying a slidable work support en' the reciprocatory slide so that the Work support may be adjusted transversely to its reciprocatory motion and I interpose a member having a slanting top between the guide and the reciprocatory slide for lifting or lowering the work piece.

As both ends of the beamare firmly clamped to thel standards, special provisions are required to enable the beam to be passed through the passage-way of the work piece or, in other words, toV slip the work piece upon therbeam.,` To this end,v

the'removal ofonel of the standards C ould be taken in consideration, as upon such removalone end of the ybeam would be exposed so that the work piece could be slipped thereupon.

However, I have found a far superiorsolutio'n-` of this problem which resides in a compositionfof' Y Y the beam of separable sections. I need only sepa- 55 larly adjustable labout 'its' longitudinal axis,V

rate one section of the beam and shift the same in the standard to spaceit from the other section whereupon the work piece may be slipped on one of the two sections. Then the sections are united again.

Further'objectsA of my invention will appear fromthe descriptionv of a preferred embodiment thereof and the features of novelty will be pointed out in the claims.

In the drawings i Y Fig. 1 is a perspective illustration of themachine, the work piece beingV omitted;

Fig.. 2 is a similar representation of the machine, the sections of the beam being separated for removalr of the finished Work piece and for attachment of a new Work piece;

Fig. 3 is a horizontal transverse section taken through the standard shown at the left of Figs. 1 and 2 and through the section of the beam mounted therein; 'f v Fig. 4 is a plan-view of the grinding head, partlyin section taken along liney 4 4 of Fig. 5;

Fig. 5 is an elevation of the'grinding head, partly in section taken along Ythe line v5--5 of Fig. 4; f

Fig. 6 is a section through a work piece taken along line 6 6 ofFig. 7;; I

l Fig. 7 is an end-view. of a Work piece, and

Fig. 8 is a vertical longitudinal section talsrenI through the Work support.

In Figs. 6 and 7 I `have illustrated atypical Work pice for the operation on which I have invented'the machine.V The Work piece is providedV Y The same Yapplies to thejfaces A grinding machine which meetshthese requirements'is shown in Fig. l in a more or lessV diagrammatic fashion. It comprises abedo'r frame lIII-onwhicli two standards I9 and'20are provided; A horizontalbeam 2| `extending. above and-'parallelto the bed. I8 has both of: its ends firmly clamped -Wthi'nfaligned bearings provided' within 'the standards. The' beam carries two grinding'discsv `22V and 23 having' their commonf spindle extending transversely-to the beam.

Either thei entire beam "or at leasta section thereof carrying the grinding wheels is-angu The faces I3`an`d I6 Vare parallelY whereby the grinding spindle may be brought either to a horizontal position as shown in Fig. 2 for work on the faces I3 and I6 of the Work piece o-r may be brought into a vertical position for work on the faces I4 and I5 of the Work piece.

The bed I8 is provided with a guide-way 24 extending below the beam 2| parallel thereto. On this guide-Way a reciprocatory slide 14 is mounted. This slide 'carries 'work-supporting means, designated as a hole by 25, which serve for adjusting the work piece relative to the slide vertically, transversely and angularly as will be described later on.

In order to enable the beam 2l to be passed .A

through the Work piece mounted onthe worksupport 25, the beam is composed of separable sections. These sections comprise a grinding head 26 carrying the grinding discs and tw rcoaxial tubes 21 and 21' extending from the opposite ends of the head 2B. tube 21 from the head 26, the tube 21 and the grinding' head attached thereto can be shifted Within the standard 2i) to the yposition shown in Fig. 2 so that 'a gap 28 will be formed through which the work piece may be passed upon the section 21' of thebearn before it is 'definitely atcached to the rwork support and adjustedA in position. VAfter the work piece has been introduced into the machine in this manner, the 'sections 21 and 21 are firmly clamped together again.

For shifting the section 21 of the beam within its bearing provided in the standard 20, suitable driving means are mounted on the standard, which inthe present embodiment com rise a pinion (not shown) Vconnected with a hand-wheel .29 and journalled-within the standard 20. This pinion engages rack-teeth l30 of the tube 21. The bearing constituted by the upper end of the standard and accommodating the tube 21-is split lengthwise and may be firmlyl clamped upon the tube by suitable clamping means which in the Apresent embodiment areconstituted by bolts 3l. .In this manner, the section 21 of the beam maybe firmly clamped in positionV after the'vvork piece has been inserted and after the beam-sections havebeen re-attached to Veach other.

The spacing of the standards I9 and 20 de.

pends on the lengthzof the 4stroke of the reciprocatory `vvork-support-25'on the frame I8, 'and this stroke is determined-byithedimensicns of the 'work piece. It is desirable,j however,ztofreduce;the.distance of the standards' to a 4minimum iii-,order l,tol enhance vthe rigidity of the mounting ofthe grinding Wheels and to increase the consequent Vaccuracy jof operation. Therefore, I preferto render the.spacing. of the standards variable so as to suit the conditions 'of'any par.- ticularwork. This object is achieved by slidably and adjustably mounting at least oneof thetwo standards on thej guide-way 24ofthe bed. Y Preferably, suitable j driving means' are providedfor displacing the standard on the guide-way 24and for clamping it thereto in adjusted position. The clamping'l means include a'hand-crank 32 shown inFigs. 1 andZ.

After Hthe work piecehasbeen slipped over Vthe section-21' of thebearn and has been attached t0. the Work-support, thebeam .section .21 Vwith the grinding-'head ,'26 is moved towards the left againpby operation of the handwheel 29, whereupon the grindingfhead is firmly attached to the tubeV 2,1' by operation of a clamping bolt 33.`

After. the machine. hes'heensetfllp nths marlnel. therslide 141s rscpwated. on the. guide-Way 24,-preferably Vby hydraulic means which are Upon detachment of Vthe wellknown in the art. In the course of the re ciprocation of the work piece the internal faces thereof are operated upon and are finished by the grinding wheels. The work piece is intermittently adjusted so that the grinding wheel in operation will remove the required amount of stock.

vIn Fig. 2, the grinding discs assume the position required for Work on the internal faces I3 and I6 of the work piece. In order to nish the internal faces I4 and I5, the operator first loosens suitable clamping bolts (not shown) which clamp the inner end of the tube 21 to the grinding head 2B and then loosens the beam section 21' from the standard I9 by releasing nuts 40 to be described later on (Fig. 3), whereupon he turns the beam-section 21 and the grinding `head 26 about the longitudinal axis by 90 degrees. The beam-sections are then firmly secured inthe new position again in which the axis of the grinding wheels isdisposed vertically. In order to accurately'determine the angular position of the beam-section 21', it is provided with an indexing mechanism, the details of which are shown in Fig. 3. Y

The outer end of thed tubular beam-section 2-1' is engaged by a sleeve `34 which is securedA against angular or longitudinal displacement in the tube by a pinl 35 and carries the -inner race of a ballbearing 36, the outer race of which is mounted in a horizontal bore of the standardv I9. The sleeve 34 has a flange to which an index disc `31 is attached by screws. The index disc carries a plurality of clamping bolts 38 having the nuts 40 mentioned hereinabove.A When vthese nuts are tightened, heads on thebolts 38 engage behind a flange 39 projecting from the standard I9 to firmly clamp the index disc and the beam-'section21 together. In order to angularly adjust the beam-section, the nuts 40 are rst loosened. v The periphery of the index disc 31 vis provided with a plurality of recesses and one of these recesses is engaged `by an index dog formed by a pin 4I slidably mounted in a bracket 42 in radial direction. This bracket is rigidly but adjustably attached to the-standard I9. 'Ifo this end, the standard is provided with la vertical guide-way 43 onwhich the bracket I2A is vertically adjustable and isl clamped in adj-usted position by bolts 44. The vertical adjustment of the bracket'42 may be effected with great accuracy by stopscrews 45 (Fig. '1), which are seated in tapped bores of suitableprojections of the standard'l9 and engage the bracket'42. By loosening the clamping bolts 44l and by adjusting the screws 45, Ythe backet'dZ/Amay be lifted or loweredand. thereby, the angular position of 'the' beam-"sectin 21 may be determined very laccurately. Should the operator, `upon commencement-0f the grinding operation, Afind 'that the v'grinding disc cuts on one side only of 'the internal face to be finished, Y'he YmustV rei-adjust 'thebeam b'y means ofthe screws`45 ntu tri 'gr'indingdsc wiil'c't over the entire v'vidthv f the'internalA face. A

The spacing Vof 'the 'recesses 4prf'nvided inthe periphery f the index VVdisc "31 amounts tov an angle 2which is Vequalfto the 'angle formed bythe intalfffaees of the work piece. yIny th'eprsent instance, this angle amounts to degrees. A le'ivre'rflY pivtally mounted in the bracket 42 engages a recessVV of the dog "4 I andsrves the purpose to disengagelthe'jsanie contrary to the action of a 'helical spring '41, if `itis desiredto adi'st"the beam. yThe 4angular adjustment ris acci'fip'lished by 4'r'rieas "f 'a suitable wrench 48 to beginserted in an opening of the index disc after the nuts 46 have been loosened and the dog 4| has been released.

The driving motor 49 of the grinding discs is accommodated in the hollow upper end of the standard I9 and is attached thereto by screws 50. This electric motor drives a shaft which is mounted coaxially within the'tubular beamsection 21 in antifriction bearings 52 and extends to the grinding head 26 to drive the grinding discs. A

The grinding head vis shown in Figs. 4 and 5. It comprises a casing 53 of rectangular crosssection provided with two opposite coaxial cylindrical projections 54 engaging into the tubes 21 and 21'. The `tubular section 21 is secured against angular displacement on the coordinated projection 54 by a suitable key engaging a notch 55 (Fig. 4). whereas the other projection 54 is rotatable within the tubular section 21. The ends of both tubular sections engaging over the projections 54 are longitudinally split and are provided with clamping screws such as 33, shown in Fig. 2. These clamping screws are tightened after the Work piece has been inserted in the machine and after the grinding spindle has been accurately adjusted. By the clamping screws 33 the three sections 21, 26 and 21 of the beam are rmly united. Through the casing 26, there extends a shaft 56 which is xed in the walls of the casing and carries a pivotal holder 51 in which aligned ball-bearings 5B are suitably attached. In these bearings, the shaft or spindle V59 of the grinding discs is journalled which extends transversely to the shaft 56 and to the beam. The ends of this spindle project through suitable openings of the casing 53 and carry bushings 60 on which the grinding discs 22 and 23 are clamped. The openings in the casing 26 are sealed by suitable means.

In the present instance, the grinding discs Yare cup-shaped working on the work piece with their rims. Moreover, the holder 51 has a ball-bearingv in which the shaft 63 of a bevel pinion 64 is journalled which is in mesh with a bevel-gear 64 attached to the grinding spindle 59. The shaft 63 is connected with the drive-shaft 5| by asuitable clutch, part of which is shown at 65.

Y TheV holder 51 ispivotally adjustable on the shaft 55. By such angular adjustment of Ythe holder, the grinding disc which is in operation at any time may be set, as desired, to either engage the face to be finished with its entire periphery or with part of its periphery only. In the first instancethe grinding marks produced on the Work piece will cross each other, whereas, in the second instance, the grinding marks are in the form of parallel arcs extending across the finished face. The accurate adjustment may be eiected by means of a shaft 66 which is journalled in the casing 53 and has a head 61 provided with bores in which a wrench 68 may be inserted for turning the shaft. The shaft has an eccentric section 69 carrying a block 10 which slidably engages parallel walls of a recess 1| provided in the holder 51. After the holder has been adjusted by suitably turning the shaft E6, the latter is clamped in position by tightening a nut 12 mounted on the threaded end of the shaft and engaging a suitable insert of the casing 53. In adjusted position, the holder 51 is rmly clamped in position within the casing 53 by means of a clamping screw 13. The clutch 65 is of the type permitting a slight misalignment of the shaft 63 and of the drive-shaft 5|,

such as is caused by a slight angular displacement of the holder 51 about the shaft 56.

The work-support 25 is illustrated in Fig. 8. It comprises a member 15 which is attached on the slide 14 and is provided with a slanting top 16 on which a guide member 11 is adjustably mounted. The guide 11 is provided at its top with a horizontal guide-way 18 extending transversely to the guide-way 24 of the bed I8. On this transverse guide 11 a work-support 19 is slidably and adjustably mounted whichis composed of two sections. These two sections and 8| are relatively pivotal and adjustable about a vertical axis.

In the member 15 there is journalled a horizontal shaft extending transversely to the guideway 24 of the bed I8. This shaft is not shown in Fig. 8, but its position will appear from Fig. l in which a hand-wheel 82 is shown which is attached to this shaft. Moreover, an inclined threaded spindle 84 is journalled in the member 15 and is geared to the shaft carrying the handwheel 82 by a pair of bevel-gears 83. A nut 88 engaging the threads of spindle 84 is attached to the guide 11. By turning the hand- Wheel 82, the operator may thus shift the guide 11 on the slanting guide-way 16 to thereby lift or lower the work piece.

For shifting the work-support 19 on the transverse guideway 18 of the guide 11, a second handwheel 85 (Fig. 1) is attached on a suitable threaded spindle journalled in the guide 11. The

threads of this spindle`are engaged by a nut attached to the lower section 80 of the work support 19. This lower section 88 carries a vertical trunnion 86 on which the upper section 8| of the work-support is pivotally mounted by means of an anti-friction bearing 81. The two sections 89 and 8| of the work-support may be relatively shifted by rotation of an eccentric (not shown) which is journalled in the lower section 80 and engages suitable stops attached to the upper section 6I. By angularly adjusting the upper section about the trunnion 86, the Work piece may be set, as required, if the opposed internal faces to be finished are not` parallel but are inclined to one another.

The work piece. may consist of any desired material, particularly of steel.

It will appear from the fore-going description that the machine is simple in design and operation, but possesses all of the properties which will ensure great accuracy in operation. Thus, the beam carrying the grinding discs being composed of coaxial tubes combines a minimum of weight with a considerable stiffness. The composition of the beam of a plurality of separable sections facilitates the mounting of the work piece considerably, since one of the tubular beam sections may be readily released from the other l section and may be then quickly withdrawn by operation of the hand-wheel 29 in order to remove the Iinished workpiece and to insert a new one. As the driving motor is mounted on one of the standards coaxially of the beam, the means for transmitting the driving motion to the grinding discs ymay be in form of a shaft thatcan be accommodated within a tubularV beam of a smallrdiameter, and the grinding head may be made much smaller than it would be possible, if the motor were included in the head. The mounting of the driving motor on one of thev standards offers the additional advantage that the beam will not be deected by the weight of the motor. The possibility of angularly ad.

Ytubular sectionv 2T with the grinding head is then turned through 90 degrees, as above described. Then, the beam sections Vare reattached whereupon the other pair of faces may be ground.

While I have described a preferred embodiment of my invention, it is to be understood that the same is not limited to the details of this embodiment but is capable of numerous modifications within the scope of the appended claims.

What I claim is:

1. A grinding machine comprising a frame, two spaced standards thereon, aligned bearings in said standards, a horizontal beam carried by and extending between said standards and constituted by separable sections, one of said sections being journalled in each of said bearings, a rotary spindle journalled in one of said sections and extending transversely thereto and carrying at least one grinding disc, means mounted on one of said standards and oooperatl allel to said beam, and a reciprocatory work table mounted on said guide-way.

2. A grinding `machine comprising a frame, two spaced standards thereon, a horizontal beam carried by and extending between said standards and composed of a grinding head and of two coaxial tubes extending from the opposite ends thereof, a spindle journalled within said head in transverse position, at least one grinding disc fixed to said spindle, a guide-way on said frame extending parallel -to said beam, and a reciprocatory work table slidably mounted on said guide-way.

3. A grinding machine comprising a frame, two spaced standards tliereon,`a horizontal beam carried by and extending between said standards and composed of a grinding Vhead and of two coaxial tubes extending from the opposite ends thereof, a holder mounted in said head to be adjustable about a transverse axis, means for adjusting said holder about said axis, aligned bearings in said holder having a commonv axis extending transversely to said beam and to said nist-mentioned axisa spindle journalled -in said bearings and carrying at least one grinding disc, a guide-wayon saidframe extending parallel to said beam, anda reciprocatory Work table slidably mounted on said guide-Way.

fi; A grinding machine comprising a frame, two spaced Vstandards thereon, aligned bearings in said standards. a horizontal beam composed of separable sections and mounted in saidbearings, a grinding disc mounted on said beam -having its axis extending at right angles thereto, meanslin-v cluding an index disc and an index dog coordinated to one of' said bearings and one of lsaid' sections for relative angular adjustrnentfclamping means for fixing said latter section in adjusted position'in its bearing, means coordinated toV the `other one of saidbearings forV longitudinally shifting one' of saidsectionsmounted therein, clam-ping means for fixing said last-mentioned section within its bearing, Va'guide-way on said frame extending parallel to said beam, and a reciprocatory Work table s lidably mounted on said guide-way. Y Y Y 5. A grinding machine comprising a frame, two spaced standards thereon, a horizontal beam carried by and extending between said standards, a grinding disc mounted on said vbeam having its axis extending Yat right angles thereto, a guideway on said frame extending parallel Yto said beam, a reciprocatory Work table mounted on said guide-way, at least one of said standards beingV slidably and Varljustably mounted on said guide-way, and-*means for clam-ping said lastmentioned standard" on said guide-way in ad justed` position. l

6. A grinding device of the class described comprising a Aframe, a pair of standards on said frame, Aan independent beam part mounted by each standard and adjustable thereto, a housing carried-by and between the beam parts predeterminedly positioned relatively to the Work and a grinder mounted by the housing.

7. The structure of claim 6 in which at least one of the beam parts is adjustable to its mounting standard in a different relationship than the remainder of said beam parts.

8. A grinding machine comprising a frame, two spacedstandards thereon, a horizontal sectional beam having a part thereof carried by each standard, means operable to adjust one part of the beam horizontally as to its supporting standard, an additional beam part mounted by the standard carried-parts and locked in lateral position as to the frame by the adjustable beam part, a guide-way on said frame extending parallel to theY beam, a grinding disc mounted on the additional beam part and having its axis extending at right angles thereto, and a reciprocatory work table mounted .on .said guide-way.

9. A grinding Vmachine ,comprising a frame, two

spaced standards thereon, a horizontal sectional beam having apart thereof carried by each standard, means operable to rotatably adjust o ne part .of the beam as to its supporting standard independently of Atheotl'ier standard carried beam part, an additional beam part mounted between the two standard carried beam parts and rotatably movable with the adjustable beam part, a guide-way on said frame extending parallel to the beam, a grinding disc mounted on the additional beam part and having its axis adjustable to a radius of any angularity in a plane extending atV right angles thereto, and a reciprocatory work table mounted on said guide-way.

10. Agrinding machine comprising Va frame, two spaced standards thereon, a horizontal multi-part beam having a part thereof carried by each standard, means operable to rotatably adjust one part as to its standard, means to horizontally adjust a second part as to its standard, an additional intermediate part mounted by and between said rst two parts and llocked into lateral position as to the frame by the horizontally adjustable part andv angularly by the rotatably adjustable part, a guide-way on said frame extending parallel to the beam, a grinding disc mounted bythe additional intermediate beam part and havingits axis in a plane at right angles thereto, anda reciprocatory work table mounted on said guideeway.

Y 11. A grinding machine comprising a frame, two spaced standards thereon, one adjustable to- I ward and from the other, -a horizontal sectionalv beam having a part thereof carried by each standard, means operable to adjust one part of the beam horizontally as to its supporting standard, means operable to adjust the other part as to its standard and additional intermediate part mounted by and between said two parts and locked into lateral position as to the frame by the horizontally adjustable part and angularly by the rotatably adjustable part, a guide-way on said frame extending parallel to the beam, a grinding disc mounted by the additional intermediate beam part and having its axis in a plane at right angles thereto, and a reciprocatory work table mounted on said guide-Way.

12. A grinding machine comprising a frame, two spaced standards thereon, a horizontal sectional beam carried by and extending between said standards, said beam having a part carried by each standard and independently adjustable, one as to the other, an intermediate beam part mounted and positioned by the standard carried parts, a guide-way on said frame extending parallel to said beam, a grinding disc mounted on the intermediate beam part and having its axis extending at right angles thereto, a motor mounted on one of said standards, and a driving connection from said motor through the beam to the grinding disc.

13. A grinding machine comprising a frame, two spaced standards thereon, a horizontal tubular sectional beam carried by and extending between said standards, said beam having a part carried by each standard and independently adjustable as to their respective mounting standards, an intermediate tubular beam part mounted and. positioned by two adjacent beam parts, said intermediate beam part having portions thereof in telescopic engagement with the two adjacent beam parts for holding said part in a fixed position, a guide-way on said frame extending parallel to said beam, a grinding disc mounted onV the intermediate beam part and having its axis extending at right angles thereto, a motor mounted in the tubular beam, and a driving connection from said motor through the beam to the grinding disc.

MAX AHNERT. 

